Magnetoelectric ignition apparatus



May 1, 193 Z G W. WALTHER MAGNETOELECTRIC IGNI TION APPARATUS Filed Dec.12, 1951 MLLUWLM U Patented May 1, 1934 UNITED STATES.

MAGNETOELECTRIC IGNITION APPARATUS Wilhelm Walther, Stuttgart, Germany,assignor to Robert Bosch Aktiengesellschaft, Stuttgart,

Germany Application December 12, 1931, Serial No. 580,662 In GermanyMarch 24, 1931 6 Claims. (01. 171-252) The invention relates to amagneto electric ignition apparatus having a stationary magnet, astationary armature, and a rotating member r having conducting pieces orsegments for the flux lines, in which the pole-shoes of the magnet aredirected parallel to-the axis of rotation of the conducting piece forthe flux lines.

The invention has for its object an apparatus which can produce eight ormore sparks per revolution. According to the invention, this is attainedby employing in known manner a rotary member having conducting pieces orsegments for the flux lines, with the rotary member having more than twosegments, and by employing a suitable formation and distribution of theiron in armature and magnet whereby only two segments at a time form thepath for the flux lines between the armature and the magnet.

An example of construction of the invention is shown in the drawing, inwhich:-

Figure l is a sectional view of a magneto.

Figure 2 a section on the line r+y of Fig. 1.

In the drawing, a denotes the stationary magnet, which consists ofseveral fiat bar-magnets having in the centre an opening for the passageof the shaft 1). The pole-shoes e of this magnet extend parallel to theshaft 1) over the rotating member 0 bearing the segments for the fluxlines, which member is secured on the shaft 1). A winding 2' is providedon the core 70 of the armature, which isalso stationary, to which corethe pole-shoes m of the armature are connected. The armature pole-shoesextend so far round the rotary member 0 that the terminal edges of thepole-shoes of the magnet and of the armature have a spacing about thecircumference of said member which corresponds to this circumferencedivided by the number of cylinders of the engine with which the magnetois to be used. The number of the segments q on the rotary member 0 forthe lines of force is half as great as the number of cylinders of theengine. The segments on the circumference of the rotary member c are ofsuch a length that they extend around the rotary member from thetrailing edge of the one armature pole-shoe to the leading edge of theother succeeding armature pole-shoe in the direction of rotation.

It therefore follows that, with the pole shoes 6 of the magnet betweenthe pole shoes m of the armature, when, in the rotation of the rotarymember 0, two opposite segments extend, as shown for the top and bottomsegments q in Fig. 2. across the pole shoes e of the magnet and from thetrailing edge of one armature pole shoe to the leading edge of the otherin the direction of rotation, there is a path for the magnetic lines offorce, from one pole shoe of the magnet, say the upper one in Fig. 2, tothe other or bottom pole shoe through the top and bottom segments q andthose portions of the pole shoes m of the armature therebetween, and thearmature will be short circuited.

It is also to be observed from Fig.2, that the spacing apart of thesegments q is less than the width, in the direction of rotation of thesegments, of the pole. shoes 6 of the magnet, so that at no time in therevolution of those segments will one pair of oppositely disposedsegments fail to come into flux-distributing relation with the magnetpole shoes and the armature pole shoes.

As already stated, when two opposite segments come into the positionshown for the upper and lower segments in Fig. 2, thelines of forceextend directly from pole to pole of the magnet through those rotorsegments and the adjacent portions of the pole shoes of the armature andthe armature core is short-circuited. This occurs also at those pointsin the revolution of the segments disposing each of the magnet shoes eacross the gap between two adjacent segments. During all other times inthe revolution of the segments, each two oppositely disposed segmentswill come into positions successively bridging the gaps on the oppositesides of the magnet pole shoes between those shoes and the armature poleshoes in a manner to so direct the magnetic flux through the armature asto produce spark impulses double the number of the flux distributersegments; or, eight spark impulses for the four-segment arrangementshown in Fig. 2. This will more clearly appear by selecting two segmentsfor consideration, those now appearing as the upper and lower segmentsin Fig. 2, and taking their revolution as clockwise. In their positionas shown in Fig. 2, these segments short circuit the armature as alreadystated. But in their clockwise revolution, what is now top segment qmoves to a position bridging the gap between upper magnet pole shoe 6and right hand armature pole shoe m, and what is now bottom segment qmoves to position bridging lower shoe e and left-hand shoe m, to providea flux path from upper shoe 6, upper segment q, right hand shoe m,armature core k, left hand shoe m and lower segment q to lower shoe e.Then when what is now the upper segment q, as the parts are viewed inFig. 2, has made nearly a complete revolution, it comes into positionbridging the gap between the shoe e and the left hand shoe m, and a fluxpath is established through the armature but in reverse direction to thefirst-mentioned path. So that each of the four segments, in cooperationwith its diametrically oppositely disposed segment, successivelyestablishes and interrupts two oppositely directed flux paths or linesof force through the armature for each revolution of the segments; and,as already pointed out, when the flux through the armature isinterrupted there is still a flux path from pole to pole of the magnet.By this arrangement the magnetic flux in the magnet is neverinterrupted, and the magnet does not become weakened.

It is, of course, to be understood that the rotary member 0 is ofnon-magnetic material, and that the segments q are of material toconduct the magnetic flux so as to function as the flux distributer.

In the operation of the magneto always two segments q only aresimultaneously traversed by the magnetic flux, whilst the other segmentsremain out of action.

The distribution of the iron in the pole-shoes of the armature andmagnet about the periphery of the rotary member 0 may, of course, beexactly the reverse of that shown without affecting the mode of workingof the magneto.

I declare that what I claim is:

1. An inductor magneto comprising, in combination, a stationary magnet,a stationary armature, a rotor having circumferentially spacedflux-conducting segments of substantially equal extent in the directionof rotation and disposed on said rotor in a plurality of pairs ofdiametrically opposed segments all lying in one plane transverse to theaxis of said rotor, pole shoes on said magnet and on said armatureextending in said plane in such circumrerentially spaced relation aboutsaid rotor as to cause each pair of segments in succession to bridgesaid pole shoes on said magnet and said armature while all the othersegments are out of said bridging relation with said pole shoes duringeach cycle of revolution of said segments.

2. An inductor magneto comprising, in combination, a stationary magnet,a stationary armature, a rotor, pole shoes extending from said magnetand said armature about said rotor in alternation of magnet pole shoeandarmature pole shoe and with said pole shoes evenly spacedcircumferentially of said rotor and all lying in one plane transverse tothe axis of said rotor, and a plurality of pairs of diametricallyopposed flux-conducting segments on said rotor of such extent andspacing circumferentially of said rotor in said one plane as to causeeach pair of segments in succession to bridge said pole shoes of saidmagnet and said armature while the other segments are out of saidbridging relation during each cycle of revolution of said segments.

3. An inductor magneto comprising, in combination, a stationary magnet,a stationary armature having a winding energized by said magnet toproduce sparking impulses, a rotor, pole shoes extending from saidmagnet and armature and a plurality of pairs of diametrically opposedflux-conducting segments on said rotor, with said shoes so disposed incircumferentially spaced relation about said rotor and said segmentsspaced circumferentially on said rotor as to cause each pair of segmentsin succession during each cycle of their revolution to so bridge saidpole shoes of said magnet and said armature and so interrupt said bridgeas to produce sparking impulses in said armature winding of double thenumber of said segments.

4. An inductor magneto comprising, in combination, a stationary magnet,a stationary armature, a rotor, two pole shoes extending from saidarmature to diametrically opposed positions about said rotor, two poleshoes extending from said magnet to diametrically opposed positionsabout said rotor between said armature pole shoes, the terminal edges ofall said pole shoes being evenly spaced apart, and a plurality of pairsof diametrically opposed flux-conducting segments on said rotor, witheach segment of an extent circum- Ierentially of the rotor just equal tothe distance circumferentially of the rotor between the adjacentterminal edges of the armature shoes on opposite sides of the rotor,said magnet pole shoes and armature pole shoes and said segments allbeing disposed to lie in one plane transverse to the axis of said rotor,whereby during each cycle of rotation of the rotor the segments of eachpair in succession with the segments of the remaining pair or pairsattain positions so bridging the gaps between the magnet pole shoes andthe armature pole shoes on opposite sides of the rotor as to direct themagnetic flux through the armature in one direction, then to direct themagnetic flux from one magnet pole shoe directly to the other throughterminal portions of the armature pole shoes in a manner to shortcircuit the armature and then to direct the magnetic flux through thearmature in a direction reverse to the first.

5. An inductor magneto comprising, in combination, a stationary magnet,a stationary armature, a rotor, two pole shoes extending from saidarmature to diametrically opposed positions about said rotor, two poleshoes extending from said magnet to diametrically opposed positionsabout said rotor between said armature pole shoes, all of said poleshoes lying in one plane transverse to the axis of said rotor and theterminal edges of all said pole shoes being evenly spaced apart in saidplane, and a plurality of pairs of diametrically opposed flux-conductingsegments on said rotor, with each segment of an extent in said planecircumferentially of the rotor just equal to the distancecircumferentially of the rotor between the adjacent terminal edges ofthe armature shoes on opposite sides of the rotor and with the segmentsspaced apart a less distance than the width of the magnet pole shoesmeasured circumferentially of the rotor, whereby at all times duringeach cycle of rotation of the rotor the segments of one or more pairsare in positions so bridging the gaps between the magnet pole shoes andthe armature pole shoes as to maintain an uninterrupted path for themagnetic flux from pole to pole of the magnet while the pairs ofsegments function successively to establish and interrupt the fluxthrough the armature.

6. An inductor magneto as defined in claim 3 and further characterizedby a disposal of said magnet pole shoes, said armature pole shoes andsaid flux-conducting segments in positions circumferentially of saidrotor all lying in one plane transverse to the axis of said rotor.

WILHELM WAL'I'HER.

